README

   1 User Management and Access Control
   2 ==================================
   3
   4 Proxmox VE implements an easy but flexible way to manage users. A
   5 powerful Access Control algorithm is used to grant permissions to
   6 individual users or group of users.
   7
   8 Best Practices:
   9
  10 Use groups in ACLs (not individual users).
  11
  12 User Authentication
  13 ===================
  14
  15 Proxmox VE can use different authentication servers. Those
  16 servers are listed in '/etc/pve/priv/domain.cfg', indexed by a unique
  17 ID (called 'authentication domain' or 'realm').
  18
  19 User names need to be unique. We create unique names by adding the
  20 'realm' to the user ID: <userid>@<realm>
  21
  22 File format 'domain.cfg'
  23 ----example domains.cfg ------------------
  24
  25 # an active directory server
  26 AD: mycompany
  27         server1 10.10.10.1
  28         server2 10.10.10.2
  29         ...
  30
  31 # an LDAP server
  32 LDAP: example.com
  33         server1 10.10.10.2
  34         ....
  35
  36 ------------------------------------------
  37
  38 There are 2 special authentication domains name 'pve' and 'pam':
  39
  40  * pve: stores paswords to "/etc/pve/priv/shadow.cfg" (SHA256 crypt);
  41
  42  * pam: use unix 'pam'
  43
  44
  45 Proposed user database fields:
  46 ==============================
  47
  48 users:
  49
  50         login_name: email address (user@domain)
  51         enable: 1 = TRUE, 0 = FALSE
  52         expire: <integer> (account expiration date)
  53         domid: reference to authentication domain
  54         firstname: user first name
  55         lastname: user last name
  56         email: user's email address
  57         comment: arbitrary comment
  58
  59         special user root: The root user has full administrative privileges
  60
  61 group:
  62
  63         group_name: the name of the group
  64         user_list: list of login names
  65         comment: a more verbose description
  66
  67 pool:
  68
  69         pool_name: the name of the pool
  70         comment: a more verbose description
  71         vm_list: list of VMs associated with the pool
  72         storage_list: list of storage IDs associated with the pool
  73
  74 privileges:
  75
  76         defines rights required to execute actions or read
  77         information.
  78
  79         VM.Allocate: create/remove new VM to server inventory
  80         VM.Migrate: migrate VM to alternate server on cluster
  81         VM.PowerMgmt: power management (start, stop, reset, shutdown, ...)
  82         VM.Console: console access to VM
  83         VM.Monitor: access to VM monitor (kvm)
  84         VM.Backup: backup/restore VMs
  85         VM.Clone: Clone VM or VM template
  86         VM.Audit: view VM config
  87
  88         VM.Config.XXX: modify VM config
  89
  90           VM.Config.Disk: add/modify/delete Disks
  91           VM.Config.CDROM: eject/change CDROM
  92           VM.Config.CPU: modify CPU settings
  93           VM.Config.Memory: modify Memory settings
  94           VM.Config.Network: add/modify/delete Network devices
  95           VM.Config.HWType: modify emulated HW type
  96           VM.Config.Options: modify any other VM configuration
  97
  98         Pool.Allocate: create/remove/modify a pool.
  99         Pool.Audit: view a pool
 100
 101         Datastore.Allocate: create/remove/modify a data store.
 102         Datastore.AllocateSpace: allocate space on a datastore
 103         Datastore.AllocateTemplate: allocate/upload templates and iso images
 104         Datastore.Audit: view/browse a datastore
 105
 106         Permissions.Modify: modify access permissions
 107
 108         Sys.PowerMgmt: Node power management (start, stop, reset, shutdown, ...)
 109         Sys.Console: console access to Node
 110         Sys.Syslog: view Syslog
 111         Sys.Audit: view node status/config
 112
 113
 114         We may need to refine those in future - the following privs
 115         are just examples:
 116
 117         VM.Create: create new VM to server inventory
 118         VM.Remove: remove VM from inventory
 119         VM.AddNewDisk: add new disk to VM
 120         VM.AddExistingDisk: add an existing disk to VM
 121         VM.DiskModify: modify disk space for associated VM
 122         VM.UseRawDevice: associate a raw device with VM
 123         VM.PowerOn: power on VM
 124         VM.PowerOff: power off VM
 125         VM.CpuModify: modify number of CPUs associated with VM
 126         VM.CpuCyclesModify: modify CPU cycles for VM
 127         VM.NetworkAdd: add network device to VM
 128         VM.NetworkConfigure: configure network device associated with VM
 129         VM.NetworkRemove: remove network device from VM
 130
 131         Network.AssignNetwork: assign system networks
 132
 133 role:
 134
 135         defines a sets of priviledges
 136
 137         predefined roles:
 138
 139         administrator: full administrative privileges
 140         read_only: read only
 141         no_access: no privileges
 142
 143         We store the following attribute for roles:
 144
 145         role_name: the name of the group
 146         description: a more verbose description
 147         privileges: list of privileges
 148
 149 permission:
 150
 151         Assign roles to users or groups.
 152
 153
 154 ACL and Objects:
 155 ================
 156
 157 An access control list (ACL) is a list of permissions attached to an object. The list specifies who or what is allowed to access the object and what operations are allowed to be performed on the object.
 158
 159 Object: A Virtual machine, Network (bridge, venet), Hosts, Host Memory, Storage, ...
 160
 161 We can identify our objects by an unique (file system like) path, which also defines a tree like hierarchy relation. ACL can be inherited. Permissions are inherited if the propagate flag is set on the parent. Child permissions always overwrite inherited permissions. User permission takes precedence over all group permissions. If multiple group permission apply the resulting role is the union of all those group priviledges.
 162
 163 There is at most one object permission per user or group
 164
 165 We store the following attributes for ACLs:
 166
 167         propagate: propagate permissions down in the hierarchy
 168         path: path to uniquely identify the object
 169         user_or_group: ID of user or group (group ID start with @)
 170         role: list of role IDs.
 171
 172 User Database:
 173
 174 To keep it simple, we suggest to use a single text file, which is replicated to all cluster nodes.
 175
 176 Also, we can store ACLs inside this file.
 177
 178 Here is a short example how such file could look like:
 179
 180 -----User/Group/Role Database example--------
 181
 182 user:joe@example.com:$1$nd91DtDy$mJtzWJAN2AAABKij0JgMy1/:Joe Average:Just a comment:
 183 user:max@example.com:$1$nd91DtDy$LANSNJAN2AAABKidhfgMy3/:Max Mustermann:Another comment:
 184 user:edward@example.com:$1$nd91DtDy$LANSNAAAAAAABKidhfgMy3/:Edward Example:Example VM Manager:
 185
 186 group:admin:Internal Administrator Group:root:
 187 group:audit:Read only accounts used for audit::
 188 group:customers:Our Customers:joe@example.com,max@example.com:
 189
 190 role:vm_user:Virtual Machine User:VM.ConfigureCD,VM.Console:
 191 role:vm_manager:Virtual Machine Manager:VM.ConfigureCD,VM.Console,VM.AddNewDisk,VM.PowerOn,VM.PowerOff:
 192 role:vm_operator:Virtual Machine Operator:VM.Create,VM.ConfigureCD,VM.Console,VM.AddNewDisk,VM.PowerOn,VM.PowerOff:
 193 role:ds_consumer:DataStore Consumer:Datastore.AllocateSpace:
 194 role:nw_consumer:Network Consumer:Network.AssignNetwork:
 195
 196 # group admin can do anything
 197 acl:0:/:@admin:Administrator:
 198 # group audit can view anything
 199 acl:1:/:@audit:read_only:
 200
 201 # user max can manage all qemu/kvm machines
 202 acl:1:/vm/qemu:max@example.com:vm_manager:
 203
 204 # user joe can use openvz vm 230
 205 acl:1:/vm/openvz/230:joe@example.com:vm_user:
 206
 207 # user Edward can create openvz VMs using vmbr0 and store0
 208 acl:1:/vm/openvz:edward@example.com:vm_operator:
 209 acl:1:/network/vmbr0:edward@example.com:ds_consumer:
 210 acl:1:/storage/store0:edward@example.com:nw_consumer:
 211
 212 ---------------------------------------------
 213
 214 Basic model RBAC -> http://en.wikipedia.org/wiki/Role-based_access_control
 215
 216 # Subject: A person or automated agent
 217 subject:joe@example.com:
 218 subject:max@example.com:
 219
 220 # Role: Job function or title which defines an authority level
 221 role:vm_user:Virtual Machine User:
 222 role:admin:Administrator:
 223
 224 # Subject Assignment: Subject -> Role(s)
 225 SA:vm_user:joe@example.com,max@example.com:
 226 SA:admin:joe@example.com:
 227
 228 # Permissions: An approval of a mode of access to a resource
 229 # Permission Assignment: Role -> Permissions (set of allowed operation)
 230 perm:vm_user:VM.ConfigureCD,VM.Console:
 231 perm:admin:VM.ConfigureCD,VM.Console,VM.Create:
 232
 233 ---------------------------------------------
 234
 235 We can merge 'perm' into the 'role' table, because it is
 236 a 1 -> 1 mapping
 237
 238 subject:joe@example.com:
 239 subject:max@example.com:
 240
 241 role:vm_user:Virtual Machine User:VM.ConfigureCD,VM.Console:
 242 role:admin:Administrator:VM.ConfigureCD,VM.Console,VM.Create:
 243
 244 SA:vm_user:joe@example.com,max@example.com:
 245 SA:admin:joe@example.com:
 246
 247 -----------------------------------------------
 248
 249 We can have different subject assignment for different objects.
 250
 251 subject:joe@example.com:
 252 subject:max@example.com:
 253
 254 role:vm_user:Virtual Machine User:VM.ConfigureCD,VM.Console:
 255 role:admin:Administrator:VM.ConfigureCD,VM.Console,VM.Create:
 256
 257 # joe is 'admin' for openvz VMs, but 'vm_user' for qemu VMs
 258 SA:/vm/openvz:admin:joe@example.com:
 259 SA:/vm/qemu:vm_user:joe@example.com,max@example.com:
 260
 261 -----------------------------------------------
 262
 263 Let us use more convenient names.
 264 Use 'user' instead of 'subject'.
 265 Use 'acl' instead of 'SA'.
 266
 267 user:joe@example.com:
 268 user:max@example.com:
 269
 270 role:vm_user:Virtual Machine User:VM.ConfigureCD,VM.Console:
 271 role:admin:Administrator:VM.ConfigureCD,VM.Console,VM.Create:
 272
 273 # joe is 'admin' for openvz VMs, but 'vm_user' for qemu VMs
 274 acl:/vm/openvz:admin:joe@example.com:
 275 acl:/vm/qemu:vm_user:joe@example.com,max@example.com:
 276
 277 -----------------------------------------------
 278
 279 Finally introduce groups to group users. ACL can then
 280 use 'users' or 'groups'.
 281
 282 user:joe@example.com:
 283 user:max@example.com:
 284
 285 group:customers:Our Customers:joe@example.com,max@example.com:
 286
 287 role:vm_user:Virtual Machine User:VM.ConfigureCD,VM.Console:
 288 role:admin:Administrator:VM.ConfigureCD,VM.Console,VM.Create:
 289
 290 acl:/vm/openvz:admin:joe@example.com:
 291 acl:/vm/qemu:vm_user:@customers:
 292
 293
 294 -----------------------------------------------